INSTRUMENTAL ARRANGEMENT TO MEASURE GRAVITY WITH GRADIENTS

Geophysics ◽  
1970 ◽  
Vol 35 (4) ◽  
pp. 713-715 ◽  
Author(s):  
Stephen Thyssen‐Bornemisza
Keyword(s):  
Gravitational Field ◽  
Theoretical Solution ◽  
Gravitational Acceleration ◽  
Gravity Gradients ◽  
Practical Application ◽  
Measuring Device ◽  
Inverse Process ◽  
Vertical Gradients

Every mass generates gravity gradients in addition to the gravitational field itself; this fact suggests that vertical gradients may be determined with a gravity measuring device based on a two‐level observation technique (Hammer, 1938; Thyssen‐Bornemisza, 1944). The inverse process, i.e. measurement of gravity or gravitational acceleration with the help of vertical gradients, apparently has not been investigated. Of course, gravity values can be computed from vertical gradients by integration (Paterson, 1961), but to actually measure gravity with vertical gradients is quite a different problem. The theoretical solution presented here provides the background for possible practical application.

A surface gravity traverse on Mars indicates low bedrock density at Gale crater

Science ◽  
2019 ◽  
Vol 363 (6426) ◽  
pp. 535-537 ◽  
Author(s):  
Kevin W. Lewis ◽  
Stephen Peters ◽  
Kurt Gonter ◽  
Shaunna Morrison ◽  
Nicholas Schmerr ◽  
...  
Keyword(s):  
Gravitational Field ◽  
Precise Measurement ◽  
Attitude Determination ◽  
Sedimentary Rocks ◽  
Gravitational Acceleration ◽  
High Porosity ◽  
Rock Density ◽  
Gravitational Fields ◽  
Gale Crater ◽  
Curiosity Rover

Gravimetry, the precise measurement of gravitational fields, can be used to probe the internal structure of Earth and other planets. The Curiosity rover on Mars carries accelerometers normally used for navigation and attitude determination. We have recalibrated them to isolate the signature of the changing gravitational acceleration as the rover climbs through Gale crater. The subsurface rock density is inferred from the measured decrease in gravitational field strength with elevation. The density of the sedimentary rocks in Gale crater is 1680 ± 180 kilograms per cubic meter. This value is lower than expected, indicating a high porosity and constraining maximum burial depths of the rocks over their history.

Relative precision of vertical and horizontal gravity gradients measured by gravimeter

Geophysics ◽  
1979 ◽  
Vol 44 (1) ◽  
pp. 99-101 ◽  
Author(s):  
Sigmund Hammer
Keyword(s):  
Survey Data ◽  
Hilbert Transform ◽  
Gravity Data ◽  
Gradient Methods ◽  
Vertical Gradient ◽  
Gravity Gradients ◽  
Relative Precision ◽  
The Hilbert Transform ◽  
Vertical Gradients ◽  
Vertical Gradient Of Gravity

Several recent publications advocate the use of the vertical gradient of gravity from gravimeter measurements at two elevations in a portable tower (Thyssen‐Bornemisza, 1976; Fajklewicz, 1976; Mortimer, 1977). Contrary opinions have also been expressed (Hammer and Anzoleaga, 1975; Stanley and Green, 1976; Thysen‐Bornemisza, 1977; Arzi, 1977). The disagreement revolves around the question of practically attainable precision of the vertical gradient tower method. Although it is possible to calculate both horizontal and vertical gradients from conventional gravity survey data by use of the Hilbert transform (Stanley and Green, 1976), it should be noted that highly precise gravity data are required. Also the need for connected elevation and location surveys, the major cost in gravity surveying, is not avoided. This is a significant advantage of the gradient methods. The purpose here is to present a brief consideration of the relative precision of the horizontal and vertical gradients, as measured in the field by special gravimeter observations.

An electronic gravimeter to measure g(r)

Geophysics ◽  
1983 ◽  
Vol 48 (1) ◽  
pp. 39-41
Author(s):  
Michael Martin Nieto ◽  
T. Goldman ◽  
Vincent P. Gutschick
Keyword(s):  
Gravitational Field ◽  
Josephson Junction ◽  
High Precision ◽  
Electrochemical Potential ◽  
Effective Length ◽  
Gravitational Acceleration ◽  
Geophysical Exploration ◽  
Acceleration Vector ◽  
Very High

We point out that a battery may be designed so that in a gravitational field it will have a gravitationally induced emf in addition to an electrochemical one. The gravitationally induced emf of a battery with a small “effective” electrochemical potential and a long “effective” length can readily be measured to very high precision by means of any precise voltmeter, and in particular by a Josephson junction. Such a device may be employed to measure any component of the gravitational acceleration vector. It can be constructed compactly enough to be placed down a borehole. Thus, in principle it is an extremely precise and adaptable tool for geophysical exploration.

Constraints on gravitational properties of antimatter from cyclotron-frequency measurements

2014 ◽  
Vol 30 ◽  
pp. 1460260
Author(s):  
Michael H. Holzscheiter
Keyword(s):  
Gravitational Field ◽  
Gravitational Force ◽  
Normal Gravity ◽  
Free Fall ◽  
Gravitational Acceleration ◽  
Technical Problems ◽  
Weak Equivalence Principle ◽  
Normal Matter ◽  
Gravitational Experiment ◽  
Fall Experiment

A fundamental question in physics that has yet to be addressed experimentally is whether particles of antimatter, such as the antiproton or positron, obey the weak equivalence principle (WEP). Several theoretical arguments have been put forward arguing limits for possible violations of WEP. No direct `classical' gravitational experiment, the measurement of the free fall of an antiparticle, has been performed to date to determine if a particle of antimatter would experience a force in the gravitational potential of a normal matter body that is different from normal gravity. 30 years ago we proposed a free fall experiment using protons and antiprotons, modeled after the experiment to measure the gravitational acceleration of a free electron. At that time we gave consideration to yet another possible observation of gravitational differences between matter and antimatter based on the gravitational red shift of clocks. I will recall the original arguments and make a number of comments pertaining to the technical problems and other issues that prevented the execution of the antiproton free fall measurement. Note that a different gravitational force on antimatter in the gravitational field of matter would not constitute a violation of CPT, as this is only concerned with the gravitational acceleration of antimatter in the gravitational field of an antimatter body.

scholarly journals The Constant of the Universe Expansion Acceleration ΓH, the Einstein Variation of c and Parameters VH, Ω, Ʌ and ɣ

2020 ◽  
Vol 12 (3) ◽  
pp. 28
Author(s):  
J. G. Lartigue
Keyword(s):  
Dark Energy ◽  
Gravitational Field ◽  
Additional Condition ◽  
Expansion Velocity ◽  
Gravitational Acceleration ◽  
Universe Expansion ◽  
Physical Universe ◽  
C Value ◽  
Space Expansion ◽  
The Universe

The Hubble-Lemaitre equation v=H∙r  (cm∙s-1) represented a linear function of the radial Space expansion velocity, if H would be a constant. Sometimes it has been assumed as H = 1/t, which sends back to the classical v = r/t. However, the later discovered acceleration required the additional condition for H to be, also, a function of time; or, opposed, the existence of a not yet defined dark energy. In a previous paper [1] it had been proposed a provisional expression for a constant Universe expansion acceleration as function of distance: Γ= H2( cm∙s-2). Now, the substitution of r as a function of time, takes to five new equations of H, the Hubble velocity vH , the Hubble acceleration ΓH and the positive Hubble potential VH of the Space. So the proposed Hubble functions for the Space: H, rH , vH, ΓH and VH result higher than those in a gravitational field. All of these Hubble functions act in the total Space expansion though, into the Physical Universe, ΓH is not perceived as it does, continuously, the opposed gravitational acceleration g. Otherwise, a revision is made of the Einstein equation for the c value as function of the gravitational potential φ. Additional proposals are made about the horizons definitions and parameters Ω, Ʌ and ɣ.

scholarly journals Plastic Deformations of Measured Object Surface in Contact with Undeformable Surface of Measuring Tool

2016 ◽  
Vol 16 (5) ◽  
pp. 254-259 ◽  
Author(s):  
Marek Kowalik ◽  
Mirosław Rucki ◽  
Piotr Paszta ◽  
Rafał Gołębski
Keyword(s):  
Plastic Strain ◽  
Digital Simulation ◽  
Theoretical Solution ◽  
Pressure Force ◽  
Measuring Device ◽  
Measured Object ◽  
Fem Method ◽  
Measuring Tool ◽  
Very High ◽  
Two Bodies

Abstract Measuring errors caused by deformation (flattening) of a measured object appear under the influence of pressure force and weight of the measured object. Plastic strain, arising at the contact of a measured object and an undeformable contact tip of a measuring device, can be calculated by applying the Hertz plastic solution and the hypothesis of plastic strain. In a small area of contact between two bodies pressing against one another with force F, there appears the so-called contact stress. It can sometime reach very high values, exceeding the yield point, even when the contact pressure is relatively small. In the present work, the authors describe a theoretical solution to the problem of plastic strain between two bodies. The derived relationships enable to calculate force F during measurements of a deformable object by means of an instrument with an undeformable, spherical measuring tip. By applying the τmax hypothesis, a solution was obtained for the force F in an inexplicit form. The theoretical solution was verified with the digital simulation and experimental measurement. With the FEM method, the limit length gage was modeled in interaction with the measured shaft of a diameter d larger than the nominal one of Δl value.

scholarly journals Joint Uses of VLBI with Astronomical Optical Instruments for Studying Vertical Changes

1988 ◽  
Vol 129 ◽  
pp. 421-421
Author(s):  
Li Zhi-sen ◽  
Zhang Guo-dong ◽  
Han Yan-ben
Keyword(s):  
Gravitational Field ◽  
Vertical Direction ◽  
Gravitational Acceleration ◽  
Absolute Value ◽  
Optical Instruments ◽  
The Earth ◽  
Effective Instrument ◽  
Vertical Changes ◽  
The Absolute

The description of the gravitational field at the surface of the Earth requires two quantities: the absolute value of the gravitational acceleration and the gravitational direction (deviation from vertical direction). At present, the various gravimeters measure the former quantity, and there is no effective instrument for monitoring the latter. This shortcoming seriously affects the comprehension and further knowledge of the gravitational field.

Gravitational acceleration of a weakly relativistic electron in a conducting drift tube

2018 ◽  
Vol 33 (33) ◽  
pp. 1850192 ◽  
Author(s):  
V. I. Denisov ◽  
I. P. Denisova ◽  
M. G. Gapochka ◽  
A. F. Korolev ◽  
N. N. Koshelev
Keyword(s):  
Gravitational Field ◽  
Relativistic Electron ◽  
Horizontal Plane ◽  
Drift Tube ◽  
Gravitational Force ◽  
Vertical Direction ◽  
Gravitational Acceleration ◽  
The Earth ◽  
Earth’S Gravitational Field

We propose the idea of method for observing the effect of the Earth’s gravitational field on the motion of an electron. Earlier attempts to measure such an effect proved unsuccessful due to the fact that under the conductive sheath, the gravitational force acting on the non-relativistic electron is completely compensated by Barnhill–Schiff force. Therefore, experiments of this kind were unable to measure the effect of the Earth’s gravitational field on the motion of electrons. In this paper, we propose to use electrons moving with relativistic speeds in the horizontal plane, and with non-relativistic speeds in the vertical direction, in which case the gravitational force on these electrons is not fully compensated by the Barnhill–Schiff force. Calculations showed that in this case, it is possible to measure the force exerted on an electron by the gravitational field of the Earth.

scholarly journals GRAVITATIONAL EFFECTS ON A RIGID CASIMIR CAVITY

2002 ◽  
Vol 17 (06n07) ◽  
pp. 804-807 ◽  
Author(s):  
E. CALLONI ◽  
L. DI FIORE ◽  
G. ESPOSITO ◽  
L. MILANO ◽  
L. ROSA
Keyword(s):  
Gravitational Field ◽  
Opposite Direction ◽  
Gravitational Acceleration ◽  
Vacuum Fluctuations ◽  
Gravitational Effects ◽  
Experimental Detection ◽  
Weak Gravitational Field ◽  
Order Of Magnitude ◽  
Cavity Configuration

Vacuum fluctuations produce a force acting on a rigid Casimir cavity in a weak gravitational field. Such a force is here evaluated and is found to have opposite direction with respect to the gravitational acceleration; the order of magnitude for a multi-layer cavity configuration is analyzed and experimental detection is discussed, bearing in mind the current technological resources.

GRAVITY GRADIENTS AND THE INTERPRETATION OF THE TRUNCATED PLATE

Geophysics ◽  
1976 ◽  
Vol 41 (6) ◽  
pp. 1370-1376 ◽  
Author(s):  
John M. Stanley ◽  
Ronald Green
Keyword(s):  
Hilbert Transform ◽  
Theoretical Data ◽  
Vertical Gradient ◽  
Density Contrast ◽  
Horizontal Gradient ◽  
Gravity Gradients ◽  
Gravity Method ◽  
Commercially Important ◽  
Dip Angle ◽  
Vertical Gradients

The truncated plate and geologic contact are commercially important structures which can be located by the gravity method. The interpretation can be improved if both the horizontal and vertical gradients are known. Vertical gradients are difficult to measure precisely, but with modern gravimeters the horizontal gradient can be measured conveniently and accurately. This paper shows how the vertical gradient can be obtained from the horizontal gradient by the use of a Hilbert transform. A procedure is then presented which easily enables the position, dip angle, depth, thickness, and density contrast of a postulated plate to be precisely and unambiguously derived from a plot of the horizontal gradient against the vertical gradient at each point measured. The procedure is demonstrated using theoretical data.

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